package homework;

import java.util.Scanner;

public class PrimeNum {
	public static void main(String[] args) {

			Scanner sc = new Scanner(System.in);
			int n, i;
			n = sc.nextInt();
			if(n == 1){
				System.out.println(n+" is not a prime.");
			}
			for(i = 2; i < n; i++){
				if(n % i == 0){
					System.out.println(n+" is not a prime.");
					break;
				}
			}
			if(i == n){
				System.out.println(n+" is a prime.");
			}
	}
	
}
